<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style>
		main{
			width: 100vw;
			height: 100vh;
			display: flex;
			justify-content: center;
			align-items: center;
		}
		div{
			width: 200px;
			height: 200px;
			background: red;
			transform: rotate(45deg)
		}
		div:after{
			content: '';
			border-radius: 50%;
			width: 200px;
			height: 200px;
			position: absolute;
			background: red;
			transform: translateY(-100px);
		}
		div:before{
			content: '';
			border-radius: 50%;
			width: 200px;
			height: 200px;
			position: absolute;
			background: red;
			transform: translateX(-100px);
		}
	</style>
</head>
<body>
	<main>
		<div></div>
	</main>
</body>
</html>